JOHANNESBURG, South Africa – South African scientists have discovered that two new sublineages of the Omicron coronavirus variant can avoid antibodies from earlier infection well enough to trigger a new wave, but are far less able to thrive in the blood of people who have been vaccinated against COVID-19.
The experts were looking at Omicron’s BA.4 and BA.5 sublineages, which the World Health Organization put on its monitoring list last month. They collected blood samples from 39 people who had been infected with Omicron when it first appeared at the end of last year.
The remaining 24 were not vaccinated, with fifteen receiving Pfizer’s injection and seven getting J&J’s.
“The vaccinated group showed around a 5-fold greater neutralization capacity…and should be better protected,” according to the report, which was issued as a pre-print over the weekend.
When unvaccinated samples were exposed to BA.4 and BA.5, antibody production was nearly eightfold lower than when they were exposed to the original BA.1 Omicron lineage. The vaccinated people’s blood indicated a threefold reduction.
Officials and scientists in South Africa said on Friday that the country may be entering a fifth COVID wave sooner than predicted, citing a continuous surge in infections that appears to be driven by the BA.4 and BA.5 Omicron sub-variants.
Only approximately a third of South Africa’s 60 million people are properly vaccinated.
“Based on neutralization escape, BA.4 and BA.5 have the potential to result in a new infection wave,” the study said.